In various medical procedures, it is desirable to direct a guidewire or other elongate medical device from one location to another location within the body of a human or non-human animal subject. For example, during endovascular treatment of chronic total occlusions (CTOs) of arteries, a guidewire may sometimes penetrate into and become embedded within the wall of the occluded artery (i.e., creating a “subintimal space” or “subintimal tract”). Often, a distal portion of the guidewire is tightly looped as it is advanced into the artery wall, thereby causing a blunt dissection or separation between tissue layers and forming a subintimal tract that has the shape of a flat or curved slit. Various reentry devices and strategies have been employed to re-direct the distal portion of the guidewire from its position within the newly-formed subintimal tract, back into the true lumen of the artery. Once the guidewire has been re-directed into the true lumen of the artery distal to the obstruction, that guidewire may then be used to facilitate the use of other catheter based devices to enlarge and stent the newly-formed subintimal tract, thereby establishing a new blood flow channel around the obstruction.
The prior art has included a number of true lumen reentry devices that are potentially useable to redirect a subintimally entrapped guidewire into the true lumen of the artery. Commercial examples of such reentry devices include the Pioneer® Catheter (Medtronic Vascular, Santa Rosa, Calif.); the OUTBACK® LTD® Reentry Catheter (Cordis Corporation, Miami, Fla.) and the Enteer™ Reentry System (Covidien/eV3, Plymouth, Minn.). Other examples are described in U.S. Pat. No. 5,830,222 (Makower); U.S. Pat. No. 6,068,638 (Makower); U.S. Pat. No. 6,159,225 (Makower); U.S. Pat. No. 6,190,353 (Makower, et al.); U.S. Pat. No. 6,283,951 (Flaherty, et al.); U.S. Pat. No. 6,375,615 (Flaherty, et al.); U.S. Pat. No. 6,508,824 (Flaherty, et al.); U.S. Pat. No. 6,544,230 (Flaherty, et al.); U.S. Pat. No. 6,655,386 (Makower et al.); U.S. Pat. No. 6,579,311 (Makower); U.S. Pat. No. 6,602,241 (Makower, et al.); U.S. Pat. No. 6,655,386 (Makower, et al.); U.S. Pat. No. 6,660,024 (Flaherty, et al.); U.S. Pat. No. 6,685,648 (Flaherty, et al.); U.S. Pat. No. 6,709,444 (Makower); U.S. Pat. No. 6,726,677 (Flaherty, et al.); U.S. Pat. No. 6,746,464 (Makower); U.S. Pat. No. 7,938,819 (Kugler, et al.); U.S. Pat. No. 8,323,261 (Kugler, et al.); U.S. Pat. No. 8,083,727 (Kugler, et al.); U.S. Pat. No. 8,241,311 (Ward et al.); U.S. Pat. No. 8,257,382 (Rottenberg, et al.); U.S. Pat. No. 8,337,425 (Olson et al.); U.S. Pat. No. 8,353,922 (Noriega, et al.) and U.S. Pat. No. 8,043,314 (Noriega, et al.).
Additionally, a recent published report describes the use of a balloon occlusion technique for diverting a guidewire from a subintimal tract into the true lumen of an artery, in lieu of using a reentry catheter. In this reported case, a 0.035 inch guidewire was initially used to form the subintimal tract that extended past an obstructive lesion. That 0.035 inch guidewire was then removed and a separate 0.018 inch guidewire was selectively advanced into the subintimal tract. A low-profile balloon catheter was then advanced over the 0.018 inch wire into the subintimal tract. The balloon was inflated to block the subintimal tract. A 0.035 inch guidewire was then advanced through the subintimal tract next to the balloon catheter. The presence of inflated balloon within the subintimal tract caused the advancing 0.035 inch guidewire to divert out of the initial subintimal tract and into the true lumen of the artery, distal to the obstruction. Although this procedure did successfully cause the 0.035 inch guidewire to re-enter the true lumen of the artery without use of a separate reentry catheter, this procedure did involve several time consuming steps and required the use of several guidewires as well as a separate balloon catheter. Additionally, as the authors note, this procedure must be performed with caution as advancement of the 0.035 inch guidewire past the inflated balloon could result in inadvertent perforation of the artery with resultant hematoma or arteriovenous fistula formation. Jaffan A. A., et al., Balloon Occlusion Of Subintimal Tract To Assist Distal Luminal Reentry Into Popliteal Artery, J Vasc Interv Radiol. 2012 October; 23(10):1389-91.
There remains a need in the art for the development of different and improved devices and methods useable for redirecting a subintimally entrapped guidewire back into the true lumen of an artery in a safe and efficient manner.